Which Hip?

Hip replacement implant options equally effective

(RxWiki News) Every year, hundreds of thousands of people across the United States undergo hip replacement surgery. When it comes to choosing a type of implant, it can be hard to sift through all the options.

No single implant option for hip replacement appears more effective than another. However, there is some evidence that metal-on-metal implants could be harmful.

"Learn your options for hip replacement."

A recent study conducted by Art Sedrakyan, Ph.D., of Weill Cornell Medical College, and colleagues shows that all the options for hip replacements - whether it be metal-on-polyethylene, metal-on-metal, or ceramic-on-ceramic - have their pros and cons.

According to Dr. Sedrakyan, hip replacement surgery has help millions of patients with arthritis or joint damage. However, many of these implants eventually need additional surgeries to fix problems like infection, wear, or dislocation.

From their analysis of 18 studies, 3,139 patients, and more than 830,000 hip replacement surgeries, the researchers found no clear advantage to choosing one implant option over another.

One study the researchers examined showed that metal-on-metal implants may lead to fewer joint dislocations compared to other implant options. At the same time, though, metal-on-metal implants were associated with a higher risk of revision surgery, compared to metal-on-polyethylene implants.

Another study showed that patients with ceramic-on-ceramic implants needed fewer revision surgeries than those with metal-on-polyethylene implants. But other data did not back up this finding.

There is evidence that metal-on-metal implants are associated with metallosis, a condition in which metal ions build up in the tissues. Be that as it may, Dr. Sedrakyan and colleagues chose not to tackle this topic in their analysis because the impact of metallosis on quality of life is still being established.

"Before any claims of benefit are made," Dr. Sedrakyan cautions, "there should be large peer-reviewed clinical trials comparing these treatments. Until then, national registries provide important real-world data that is critical for the safety and future comparative safety and effectiveness evaluation." In other words, we cannot know which implant options are better until researchers conduct side-by-side comparisons of the implants. Until more research is conducted, our best gauge of effectiveness has to come from large sets of data, such as those used in this study.

In order to tackle the problems associated with hip implants and other orthopedic devices, the FDA's Center for Devices and Radiologic Health has started the International Consortium of Orthopedic Registries. The goal of creating the consortium is to improve the safety and effective of devices like hip replacement implants.

The study by Dr. Sedrakyan and colleagues was funded by the FDA. The results are published in the journal BMJ

Review Date: 
November 30, 2011